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Old 03-11-2013, 09:45 PM   #27 (permalink)
Grrr :-)
Nerys's Avatar
Join Date: May 2008
Location: Levittown PA
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Cherokee - '88 Jeep Cherokee
90 day: 19.44 mpg (US)

Ryo-Ohki - '94 Geo Metro Xfi
90 day: 50.15 mpg (US)

Vger 2 - '00 Plymouth Grand Voyager SE

Ninja - '89 Geo Tracker
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the biggest problem with any sort of alternative charging methods is POWER demands. most moderns cars simply demand too much power.

I was thinking about and still might try and use the exhaust to charge my car but not in the way you might think (too expensive for my budget right now but working on it theoretically at least)

First low power car. namely my geo metro and my geo tracker. they already only have two pulley driven items. water pump and alternator.

First ditch the water pump in its place an electric water pump (not nearly as power hungry as you think 6amps and you can REALLY cut that back since its made for a V8 engine!!) I bet at 2 amps it would still be more than we need for out little engines.

second alternator. ditch it. now how do you charge. well first of all if you REDUCE Power consumption enough you might not even NEED to worry about charge. just install a second battery both deep cycle and be done with it. plug it it when you get home. in the summer a geo metro I estimate can go a week between charges depending on how much night time driving one does.

that brings up THE LARGEST power draw in the car short of the starter and the regular "keep alive" systems. LIGHTS. a single brake light is 21-27 watts of power !! 2 amps. how many BULBS are in your car again? do the math. its HUGE. so just replacing all your bulbs with LED will bring your total demand lighting down from HUNDREDS of watts to a few watts.

the last don't forget the interior light and all those little but VERY power hungry dash bulbs !! (I am at this stage now working on replacing all the bulbs)

next up HEADLIGHTS. this one is a lot trickier. getting enough lumens from 10w led's to see on the highway is chidishly easy and cheap.

what is NOT so easy is getting the right "optics" to create a usable and SAFE for both you and other drivers BEAM pattern. this is the hard part. once we solve this now your chewing 20watts low beam instead of 100 watts !!!

so how do you replace the charge? well I got 2 30watt amorphous (red) solar panels. these work in low light !! so more charging. one on the roof of each car (easy on the tracker with its flat room have not checked fit on the metro) that takes care of some of the power that panel will make me 300 watts of power every day. in fact it alone might be enough save for the blower motor (big power pig)

so my last thought was MAN all that HEAT going out the exhaust pipe. can't I USE that somehow. and then it hit me.

Peltier Coolers !! we use them overclocking computers. they create temperature gradients when you apply power to them (one side gets hot one side gets cold and you dissipate the hot side to keep the cold side colder)

these ALSO work in REVERSE !! if you HEAT UP one side and "COOL" the other side and create a temperature gradient YOU GET POWER out of them. ie they are generators.

think about making your exhaust pipe SQUARE and lining the bottom with these Peltier's with cooling fins in the air stream below the car. that is one heck of a temperature gradient.

the trick is finding affordable Peltier's that can handle those kinds of temperatures. SO exactly how HOT does the exhaust get ?? As soon as I find my ir thermometer I will find out :-)

now your turning your exhaust heat into power back into the battery WITHOUT blocking or restricting the exhaust at all. don't forget your zener diodes so the battery does not drain down POWERING the Peltier's :-)

that is where I am at in the theoretical department for now.

ideas ?
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